Over gassed FAL

[Visceral_Malice]

I have a caliper I used for reloading. I have 2 pistons as well. I bought a second one and have never actually run it as it was initially binding up in the gas tube as well. It led me to think it might be the gas tube until I had taken it off and put it back on and the problem vanished. I can definitely take a measurement when I get home later.

[Visceral_Malice]

Both piston heads measure in about 0.430"

[SgtStrykerUSMC43]

A little under or over .430"?

[Visceral_Malice]

Best I can tell is right on it +/- .001. My caliper fluctuates between .429-.431 while measuring.

[falister]

The best thing to do is restrict the gas port as they have obviously drilled too big a hole. With the regulator unscrewed all the way and it still holds open on the last shot, then everything appears to be working well except too much gas. You should probably remove the gas block and take a closer look at the port size, I'm assuming it's bigger than standard. Standard Belgium issue metric port size is 2.5mm (about 100 thou), the standard issue L1A1 inch gas port is about 94 thou. Pic is of a unissued new Belgium metric gas block with a long 100 thou drill bit in it. I also checked a few Fal barrels I have laying around and the metric versions are a little different between countries of manufacture but you should start with the 100 thou size gas port hole and it should be all good. The great thing about the FAL is that it has a adjustable gas system so best to restore that feature to proper function, it will be much better to fire with less felt recoil, last a lot longer and if you reload your brass will last longer too. fal gb 001.JPGfal gb 003.JPGIf you restrict the gas port and you have the other problem of not enough gas then remove front sight and drill through the provided hole there, like pics show and that will save you removing gas block again. Test as normal FAL procedure by closing gas regulator click by click until weapon holds open on the last shot, then add 2 more clicks and go shoot.

[Visceral_Malice]

Thanks so much for the help guys. I have one last question: Is there a trick to getting the pin out of the gas block for removal? I have been on it with a punch and hammer pretty hard and it doesn't seem to budge.

[SgtStrykerUSMC43]

Thanks so much for the help guys. I have one last question: Is there a trick to getting the pin out of the gas block for removal? I have been on it with a punch and hammer pretty hard and it doesn't seem to budge.

The pin is tapered and press fit. The gas block is also a press fit onto the barrel so if you don't have at least and arbor press, don't attempt it. If you do manage to get it off, how would you index it before pressing it back onto the barrel without the fixture?

Before you start hammering, check the port diameter. That's why I asked if you had pin gauges available. The gas port diameter (according to Steyr & FN spec) is to be set at .0787" +.0002". The port in the gas block is of course, larger...

As I stated, just get a Buffer and you'll be okay. The gun isn't going to beat itself to death.

.02

[Visceral_Malice]

The pin is tapered and press fit. The gas block is also a press fit onto the barrel so if you don't have at least and arbor press, don't attempt it. If you do manage to get it off, how would you index it before pressing it back onto the barrel without the fixture?

Before you start hammering, check the port diameter. That's why I asked if you had pin gauges available. The gas port diameter (according to Steyr & FN spec) is to be set at .0787" +.0002". The port in the gas block is of course, larger...

As I stated, just get a Buffer and you'll be okay. The gun isn't going to beat itself to death.

.02

Gotcha. I just had seen a few build threads where it was removed and put back on using a wood block and hammer with the receiver in a vice. I'll give the port a check and see what I can do.

[Visceral_Malice]

Resurrecting my own thread here. I tore my FAL down to every little bit and piece last night to do some work on it and I finally got around to measuring the gas port on the barrel. Its about 2.65mm or 0.104". Obviously over sized. Anyway would it be advantageous for me to just drill out the vent on the gas block a little? Seems like that might solve my issue. Also the damn muzzle brakes on the century FALs are a real pita to get off. So much dremeling!